The environmental effects of dental amalgam

Dental amalgam is one of the most commonly used materials in restorative de ntistry. However, one of its major components, mercury, is of particular co ncern due to its potential adverse effects on humans and the environment. I n this review, the environmental impact of dental amalgam will be discussed , with particular reference to the effects attributed to its mercury compon ent. Mercury commonly occurs in nature as sulfides and in a number of miner als. Globally, between 20,000-30,000 tons of mercury are discharged into th e environment each year as a result of human activities. According to a rec ent German report, approximately 46 per cent of the freshly triturated amal gam is inserted as new amalgam restorations and the rest is waste. Dependin g on the presence of an amalgam separating unit, some of the generated amal gam-contaminated sludge is discharged into the sewage system. Lost or extra cted teeth with amalgam fillings and amalgam-contaminated waste, such as tr ituration capsules and cotton rolls are discharged with the solid waste and , in most instances, are incinerated. Use of disinfectants containing oxidi zing substances in dental aspirator kits may contribute to remobilization o f mercury and its subsequent release into the environment. Nevertheless, de ntal mercury contamination is only a small proportion of terrestrial mercur y (3-4 per cent), which is quite insignificant compared with industrial pol lution and combustion of fossil fuels by vehicles. The environmental impact of dental mercury is mainly due to the poor management of dental amalgam w aste. Proper collection of mercury-contaminated solid waste prevents the re lease of mercury vapour during combustion. In addition, the use of amalgam separating devices reduces the amount of amalgam-contaminated water release d from dental clinics.